Or, just do what I had done and cut the pipe after the O2 sensors and go true dual. Makes a beautiful sound with 2x2.5" in/out 29.5" length 3.5" diameter Cherry Bomb Glasspacks.

 

Duals definately have their place. But if you are interested in low end torque, then duals don't make the cut.

 

I still haven't looked at the Y on mine, but I am sure that it is the same as pictures. Looking at the exhaust on these cold morning, I can tell that the stock exhaust flows pretty good.
I do not plan on removing my stock y-pipe because that restriction at the y is just enough to create the proper backpressure for more torque. I do not drive at 5500rpm much, so I do not need a high flowing exhaust like I have on the Mustang.
I do tow about 7K at times and I need the torque over the HP. I will eventially install the Magnaflow cat-back because I like the sound and it is a stainless kit.

 

H-pipe for torque
X-pipe for higher rpm hp.

H sounds better too. Deeper tone.

 

How much more tq would an aftermarket h-pipe produce versus an aftermarket y-pipe. I am working on turning my 4.7 into a tq monster.

 

I don't mean this in a disrespectful way... but you don't fully understand how your exhaust works.

The problem with the stock Y is that it puts more of a kink into the drivers side of the exhaust, then it does the passenger side. This creates uneven back pressure. Additionally, the drivers side is longer than the passenger side to start with, which creates even more uneven back pressure.

I tow a 25' cabin cruiser. So I understand torque and towing needs. While it's true that back pressure helps with torque. More is sometimes less. In this case, the poorly designed factory Y is "more". I saw and felt a significant difference when I changed my Y.

If you want to carry this to extremes... would you install a 1" exhaust to maximize torque? Of course not. The factory Y is simply a cost cutting measure, not a performance enhancing engineered design.